The UCSC graduate training program in Molecular, Cellular, and Developmental Biology provides intensive training in the skills necessary for outstanding research in modern biology. First year trainees undertake coursework emphasizing critical evaluation of scientific models and experimental results, and they also participate in three ten-week laboratory rotations. Second-year students take an oral qualifying exam, and advanced students participate in a variety of seminars, advanced special topics courses, and research group meetings designed to provide continuing learning opportunities. The goal of the training program is to produce graduates who have a strong foundation in the specific area of their thesis research, as well as broad training and knowledge in molecular, cellular, and developmental biology. The program is administered by Advising and Admissions Committees according to policy guidelines stated in our Graduate Handbook and Faculty Guidelines. The training program is composed of 19 members of the Department of IVICD Biology, and 9 affiliated faculty from the Departments of Biomolecular Engineering, Chemistry and Biochemistry, and Microbiology and Environmental Toxicology. The majority of the faculty members are housed in the Sinsheimer Laboratories, with other faculty located in the Physical Sciences Building, which is adjacent to Sinsheimer Labs. The MCD training program provides an interactive and collaborative research environment for graduate training. Research in the training program utilizes a wide variety of approaches and model organisms, and is organized as interdisciplinary clusters of faculty with shared interests, thereby creating critical masses of researchers that foster mutual support and scientific interaction. During the first 10 years of NIH training support we have recruited and trained outstanding students who would be amongst the best students in any training program. We are requesting a total of 8 predoctoral trainee positions in this renewal, which will continue to be awarded to our best students. Relevance: Students in the MCD Biology training program have extensive opportunities to study topics related to human health. Many training faculty work on systems that are directly relevant to human health, including stem cell biology, malaria, cholera, cancer biology, host-pathogen interactions, neurodegenerative diseases, and the responses of neurons to stroke and other damage. Other faculty carry out basic research that provides the foundation for understanding topics relevant to human health, including research focused on cell division, signaling, meiosis, chromatin remodeling, cell differentiation, and neurobiology.